These studies attempt to relate the organization of basal glanglia outputs to the well documented differential organization of neurological substrates controlling the axial musculature vs those controlling the distal musculature. This axio-distal organization may play a role in the initiation of voluntary movement by the basal ganglia and motor cortex. Recent electrophysiological studies revealed a topographic axio-distal distribution of motor cortex outputs to the caudate nucleus. Experiments carried out during this year revealed how this axio-distal sorting within the caudate nucleus is reflected in the striatal outputs (via the entopeduncular nucleus in the cat) to the thalamus, and how this projection interacts with that of the cerebellar projections to the thalamus. Experiments proposed for the coming year, will determine whether or not mesencephalic basal ganglia projections are also organized in a topographically functional manner.